The development of innovative molecular techniques such as pulse-field gel electro- phoresis, cDNA subtraction libraries and chromosome hopping libraries coupled with the increasing popularity in the prospect of sequencing mammalian genomes, has triggered a resurgence of interest in finding and characterizing genes that playa role in modifying immune processes and diseases. Genetically defined strains of mice (e. g., inbred strains and recently derived stocks of wild mice) provide ideal models for examining the genetic control of diseases as a result of their syntenic relationship with man in...